Researchers Show Effects Of Long-Term Marijuana Use On The Brain

Long-term marijuana use affects the brain, but the exact effects may depend on duration of use and the age when cannabis was first consumed, according to researchers from The University of Texas at Dallas’ Center for BrainHealth.

In a study published in the journal Proceedings of the National Academy of Sciences, Francesca Filbey and colleagues comprehensively describe for the first time brain structure and function abnormalities arising from long-term marijuana use.

Utilizing several MRI techniques, the researchers determined that long-term marijuana users tend to have smaller orbitofrontal cortices, the region of the brain usually connected to addiction. However, they also exhibited an increased connectivity in the brain. And the heavier the marijuana usage, the greater these brain connections were.

“The results suggest increases in connectivity, both structural and functional that may be compensating for gray matter losses,” said Sina Aslan, one of the authors of the study.

The researchers also observed that structural connectivity in the brain starts to degrade after marijuana use was continued for between six and eight years, but these brain connections in users are more intense than what non-users have. This might be the reason why long-term marijuana users appear to be fine despite the reduced volume in their orbitofrontal cortices.